1. Field of the Disclosure
The current invention relates to an air conditioner providing cooling by way of liquid evaporation. The air conditioner is optionally powered by solar energy.
2. Description of the Related Art
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.
Nowadays, air conditioners have become one of the essential items in residential and office buildings. Air conditioners provide a pleasant living or working environment by dehumidifying and lowering the temperature in the local area. Air conditioners commonly employ an electric motor to drive a compressor that compresses and circulates a refrigerant in the air conditioning system. However, it is widely known that the compressor consumes more energy than other electric appliances.
As industrialization continues in underdeveloped part of the globe, demand for air conditioners is expected to grow worldwide in the future. Experts are concerned on energy shortages due to this increasing trend in energy consumption. In particular, the prediction that fossil fuels could be completely depleted within next couple of decades has triggered an imminent need for development of alternative energy sources along with more energy efficient appliances including air conditioners.
Moreover, there have been environmental concerns raised on chemical compounds such as R-12 (also known as Freon) which was widely used as refrigerants in air conditioners and refrigerators, and this issue caught worldwide attention because R-12 is deemed hazardous to the environment by posing a threat to the ozone layer. Consequently, more environmentally friendly air conditioners are highly desired.
An example of environmentally friendly cooling is evaporative cooling. The principle of evaporative cooling has been known for centuries. An example of evaporative cooling is cooling by human perspiration. Humans have pores in the skin from which liquid water internal to the skin is escaping and converting to water vapor in the air. As this happens, there is a cooling effect on our skin surface. For another example, a water soaked cloth placed over an object keeps the object cool by evaporation of water from the object. When evaporation occurs from a surface, there is an energy associated with the phase change known as the latent heat of vaporization. In a given system, as a gas species flows over the wet surface, evaporation and condensation continuously occur to maintain steady-state conditions. In order to sustain evaporation, there must be a draw of internal energy in the liquid, which would result in a temperature reduction. This cooling effect is known as evaporative cooling and is most effective in dry climates due to the lack of moisture content (relative humidity) in the air.
A device called zeer pot is another example making use of the effect of evaporative cooling. The zeer pot is typically made of clay and consists of an inner pot, an outer pot, wet sand between the inner pot and the outer pot, and a wet cloth on top. The zeer pot cools as the water evaporates allowing food stored in the inner pot to be kept fresh for much longer in a hot and dry climate, and is normally placed in a dry and ventilated space for the water to evaporate effectively towards the outside.